TH900mk2
- Driver
- Dynamic
- Enclosure
- Closed-back
- Weight
- 390 g
- List
- $1,499.99
A closed dynamic in Japanese cherry birch, lacquered with urushi by Sakamoto Otozo Shoten in Bordeaux with silver foil. The 50 mm driver pairs a bio-cellulose diaphragm with a 1.5 tesla magnetic circuit. Fostex lists it as discontinued.
Discontinued by the maker. Retailers may still hold stock. Current alternatives are listed below.
Where to buy
List $1,499.99
None of the boutiques we track list this model right now. Manufacturer page: fostex.jp.
Retailer prices checked 2026-10-21. We may earn a commission on purchases. How this works
Title block
- Maker
- Fostex
- Model
- TH900mk2
- Made in
- Japan
- Released
- 2016
- Transducer
- Dynamic
- Enclosure
- Closed-back
- Driver
- 50 mm
- Weight
- 390 g
- Impedance
- 25 ohms
- Sensitivity
- 100 dB/mW
- Frequency response
- 5 Hz – 45 kHz
- List price
- $1,499.99 USD
Drive requirements
Match an amplifier in the synergy calculator| Level | Power | Voltage | Current |
|---|---|---|---|
| 100 dB | 1.00 mW | 0.16 V | 6.32 mA |
| 110 dB | 10.0 mW | 0.50 V | 20.0 mA |
| 120 dB | 100 mW | 1.58 V | 63.2 mA |
Most headroom at 110 dB
- ampsandsound Bigger Ben (Rev 3, 2026)+33.1 dB
- HeadAmp GS-X mk2+29.0 dB
- Woo Audio WA33 (2nd generation)+28.9 dB
Rated 100 dB/mW into 25 ohms. Estimated from published amplifier output.
Assembly drawing
Parts
- 1HeadbandProtein leather (Sonarworks review; Fostex does not specify)
- 2Ear cupJapanese cherry birch (mizume-zakura) housing, urushi lacquer Bordeaux finish with silver foil
- 3MagnetNeodymium, repulsive-field magnetic circuit, 1.5 T flux density
- 4DiaphragmBiodyna bio-cellulose fiber diaphragm
- 5EarpadsProtein leather with low-resilience cushion
Schematic dynamic assembly, annotated with the Fostex TH900mk2’s published materials. Not to scale.
Engineering notes
- Biodyna diaphragm made from bio-cellulose fiber blended with other fibers
- Neodymium magnetic circuit using a repulsive magnetic field, 1.5 tesla flux density, in a 50 mm driver
- Housing cover lacquered with urushi by Sakamoto Otozo Shoten (founded 110 years ago); housing wood is mizume-zakura
- Detachable 2-pin 3 m 7N-OFC cable with duralumin plug sleeve (mk2 change from the original TH900)
Design language
A craft object first: deep red urushi over cherry birch, polished to a glass-like depth.
Build the listening station
Desktop sanctuaryAmplifier
Woo Audio WA22 (2nd gen)
Anodized aluminum chassis, PTFE tube sockets, ALPS RK27 pot
from $2,699
stand
Grovemade Wood Headphone Stand
American walnut, veg-tan leather, 304 stainless steel, cork feet
from $220
cable
Moon Audio Silver Dragon
UP-OCC silver with Kevlar, Teflon insulation, Cardas silver solder
from $825
Current alternatives
Dynamic
$4,999
Utopia (2022)
Beryllium, Carbon fibre, Leather
- Enclosure
- Open-back
- Drive
- Easy drive
- Weight
- 490 g
Dynamic
$2,999
Stellia
Beryllium, Aluminium, Stainless steel
- Enclosure
- Closed-back
- Drive
- Easy drive
- Weight
- 435 g
Dynamic
$2,495
Signature HP100 SE
Aluminium, Stainless steel, Leather
- Enclosure
- Open-back
- Drive
- Easy drive
- Weight
- 520 g
Dynamic
$2,199.95
HD 820
Glass
- Enclosure
- Closed-back
- Drive
- Easy drive
- Weight
- 360 g